The Study Of Permanent Magnet Synchronous Motor Sensorless Control System

In recent years, interior permanent magnet synchronous motors have been widely used due to their high power density, high efficiency and easy of control, etc. In order to achieve the vector control of IPMSM, the precise position of the rotor is required to control speed and torque. In common application, the rotor position can be obtained by using mechanical speed (position) sensors, like an encoder or a resolver. Unfortunately, the use of these mechanical sensors not only increases the cost and weight of the system, but also reduces the reliability and noise immunity of the system. The sensorless control of IPMSM is beneficial because that it can make the system cheaper and more reliable. So the sensorless control of interior permanent magnet synchronous motors (IPMSMs) has been a research area of significant interest.Firstly, this paper introduces the research background and the development of PMSM drive system. On the basis of the classical mathematical model, this paper introduces three common vector control strategies and analyzes the advantages and disadvantages of the three ones. Then a best one is selected.Secondly, this study describes the active flux concept, which is used to design a rotor position and speed observer. A multitude of solutions have been proposed for sensorless operation, but most of them fail to deliver satisfactory performance in the low speed region. The observer does not require any speed adaptation. So speed estimation errors especially in the low speed region do not affect the performance of the observer. At the same time, the weakness of PI control strategy is analyzed, and a fuzzy PI controller is designed on the base of fuzzy logic. The simulation is proposed by MATLAB/SIMULINK.At last, the paper gives hardware circuits, soft flow and the experiment wave of the IPMSM drive system. The experiment results indicate that the sensorless control algorithm is effective and practical.